Thread: Casting enumerated type to integer query

Pretty sure it's crazy to cast a plain integer to an entire enumerated type.

What do you mean by "entire enumerated type"?
Is it crazy to cast a "plain integer" to an "entire floating point type"?

Do you understand what an enumerated type is?
Enumeration declaration - cppreference.com

Still not why you couldn't just assign it though, and why you need to use a cast instead

You can assign it 0 in C without a cast, but the C++ type system is more restrictive so that things like function overloading (which doesn't exist in C) work properly. Also, if you can easily assign an integer to a Weekday type you can easily assign an incorrect value, i.e., one that doesn't have a constant name defined. It's best to assign one of the constants directly.

Code:

#include <iostream>

enum Weekday { Sunday, Monday, Tuesday };

void print(Weekday d) {
    using std::cout;
    cout << "Weekday: ";
    switch (d) {
    case Sunday:  cout << "Sunday";  break;
    case Monday:  cout << "Monday";  break;
    case Tuesday: cout << "Tuesday"; break;
    }
    cout << '\n';
}

// Same function name, different argument type
void print(int d) {
    std::cout << "int: " << d << '\n';
}

int main() {
    Weekday day = Sunday;
    print(day);
    print(0);
}

Or even something like the following where operator<< has many overloads.

Code:

#include <iostream>

enum Weekday { Sunday, Monday, Tuesday };

std::ostream& operator<<(std::ostream& os, Weekday d) {
    switch (d) {
    case Sunday:  os << "Sunday";  break;
    case Monday:  os << "Monday";  break;
    case Tuesday: os << "Tuesday"; break;
    default: os.setstate(std::ios_base::failbit);
    }
    return os;
}

int main() {
    Weekday day = Monday;
    std::cout << day << '\n';
}